Clyde Tombaugh

In the early 20th century, Percival Lowell conducted an extended search for a ninth planet, but was unsuccessful.

After his death, his successor Clyde Tombaugh continued the search by systematically photographing the heavens night after night at Lowell Observatory.

Since planets move relative to the background stars, any undiscovered planet would appear in a different location in two images taken at different dates.

Tombaugh used a machine called a blink comparator that would allow him to switch plates back and forth, hoping that the eye would be able to detect any star that appeared to move between the two plates.

I don't know.

You, you mentioned, uh, y- your, your history in astrophysics, and I'll probably mispronounce his last name, but Clyde Tombaugh or Tombaugh, the guy that discovered Pluto.

Oh, okay.

Uh, a- anyway, my son was fascinated with him as a child.

At the beginning of the 20th century, there were theories about strange things about the orbit of Uranus and Neptune, and it caused astronomers to say, hey, there might be something out there that's exerting enough gravity that it's causing the peculiar wobble and the other little oddities in the orbits of those planets.

Well, fast forward to 1930 when astronomer Clyde Tombo spotted something out there, and indeed it was confirmed there was a ninth planet.

They named it Pluto.

And it remained a planet for some time.

But knowing something should exist and actually finding it are different problems entirely.

For decades, the only known object beyond Neptune was Pluto, discovered in 1930 by Clyde Tombaugh.

Pluto was classified as the ninth planet for 76 years, and during that time it seemed like a lonely outpost, a single, small, icy world orbiting at the edge of everything.

Astronomers searched for companions but found nothing.

They knew Pluto had a thin atmosphere and a large moon called Chiron, but the details, the geology, the texture, the actual landscape were completely unknown.

Pluto was a smudge.

It had been a smudge for 85 years, ever since Clyde Tombaugh first spotted it as a faint dot drifting slowly across photographic plates in 1930.

The prevailing expectation was modest.

This is not the first time humans have seen Pluto.

Pluto was discovered in 1930 by a young astronomer named Clyde Tombaugh working at Lowell Observatory in Arizona.

Tombaugh spent months comparing photographic plates of the night sky, looking for a tiny point of light that moved against the background stars.

When he found it, the discovery made international news.

And the stages did not begin with Webb.

They began nearly a century ago, and each improvement in observational capability made Pluto less comfortable, not more.

When Clyde Tombaugh discovered Pluto in 1930, it was a point of light on a photographic plate, nothing more.

It could have been anything.

So what's about Pluto that's so amazing? In school, my instructor was the discoverer, Dr.

Clyde Tombaugh.

He passed on, and they sent the spacecraft called New Horizons.

But why demote an object like this? It's only 1,473 miles in diameter, smaller than the moon, and if you were able to land there, 5%, like I mentioned, of the astronomers in the world, or 4 or 5%, voted to change it.